Doing a bit of cleaning under the bonnet today, just caught the cylindrical valve with a rag and the hose ringed in red pulled off the valve spigot. On closer inspection the hose was so loose on the spigot you could wobble it from side to side. Should this connection be airtight? I secured it for the time being with a few cable ties.

 

It'll be fine with a few cable ties as long as none of them are split

 

Part of the purge system and as it's connected to the inlet manifold needs to be airtight
For reference

 

would this have altered the performance of the engine?

 

Quite possible